Absolute distance measurement by spectral interferometry through wavelet transform with frequency comb

Wavelet transform (WT) was exploited to measure distances based on spectrum interferometry. Complex Morlet wavelet was used as the mother wavelet to obtain the amplitude graph and phase graph simultaneously, and the latter showed the wrapped phase in fact. The distances were measured numerically and experimentally, and each distance for ten times. Experimental results indicated that the distance could be obtained uniquely using wavelet transform, and the reproducibility deviation was 77.7 nm when the measured distance is about 1 mm.